Locking device



W. R. SCHERB April 16, 1946.

' LOCKING DEV'ICE Filed July 8, 1944 2 Sheets-Sheet 1 FIG. I

WJP. SCHERB,

ATTORNEY April 16, 1946. w. R. SCHERB 2,398,466

1 LOCKING DEVICE Filed July 8, 1944 2 Sheets-Sheet 2 FIG. 3

,4 Tram/Er Patented Apr. 16, 1946 UNITED STATES PATENT OFFICE:

LOCKIN G DEVICE Walter R. Scherb, Silver Lake, N. 35., assignor to Western Electric Company, Incorporated, New York, N. Y'., a corporation-of New York Application July 8, 1944, Serial-No. 544,089 r 2 Claims.

This invention relatesto a locking device, and more particularly to an arrangement for looking a member removably in place on a support.

In the manufacture of quartz crystal slices for use in electrical apparatus, the slices are often subjected to a lapping operation on the larger flat faces of the slices. To this end a crystal slice may be mounted on a holder whose body is cylindrical in form and on which holder the slice may remain through several operations including the one of lapping. The holder is clamped,

for lapping, on a supportoperatively adjacent to a suitable lapand relative motion of the support and Iapis employed to efiect the lapping. To ensure suitably even reduction of the surface being lapped, it may be desirable to be able to change the angular position of theholder in the support with respect to the axis of the cylindrical body of the holder.

An object of the invention isto'provide a device to hold a member, erg. acylindrical bodied crystal slice holder, securely but easily removably in place on a base member, erg. a crystal holder support on a crystal lapping machines Withv the. above and other objects in view, the invention may be embodied in a clamping device to exert pressure on an element to-hold the same against a rigid support,- a screw threaded base member to be received in a correspondingly threaded bore in the support, a clamp member mounted on the base member with freedom to reciprocate thereon axially thereof but without freedom to rotate therewith and dimensioned to overhang an element in position to be clamped against the support, resilient means to urge the clamp member along the base member away from the support, and means mounted on the base member and actuable in one manner to force the clamp member toward the support to clamp an element thereagains-t or to release the same and actuable in another manner to rotate the base member to swing theclamp member to bring the clamping overhang thereof outof or into operative position.

Other objects andfeaturesof the invention will appear from. the following detailed description of one embodiment thereof taken in connection with. the accompanying drawings, in which the same reference numerals are-applied to identical partsintheseveral figures and in which Fig, 1 is a detached plan viewwith parts broken away of an illustrative' embodiment ofthe invention;

Fig.2 is a front Fig. i, and

Fig. 3 is a section on the line -3- ofFig. 1,

As herein illustrated; the invention is shown asapplied to the crystal holder support ofa crystal lapping machine. Qnly this 's upp'ort is shown as the embodiment of the invention'here disclosed requires no more for an understanding of the invention, other p'artfs and the general function of the machine being no part of the invention.

So far as present purposes are concerned, the

elevation of the showing of crystal-holder support; generally indicated at It,

comprises a tabular member or'table l 'l", triangularly symmetrical about-the axis of a shaft l2 perpendicular to the: table H at its center." The table I I consists of three identically similar and identically similarly furnished sectors or lobes of which, therefore, only one is necessary tobe described "'I fhelobe in question presents a recess I AIinitsperiphery having the form, general- 1y; of a rightangled notch with itscorner rounded off. contact-inserts 15, 1-5 of hard material, e.- g. tungsten carbide, are mounted in the sides of the recess 1-4 to have their-outer faces parallel to: the sides of tnerecess but projected a little within the recess, all these parts being so arranged and dimensioned that the generally cylindrical-body 16' or a crystal holder, when pressed sidewise into the recess [4 with the axis of the body I6 parallel to the axis of the shaft [2, will make contact against the inserts l5; 15 along ele ments'ofthecylindrical surface oi thebody about ninety degrees 090) apart. Grdinarily there will: be a; positioning pin= Fl rigidly mounted in the table It to project into' the recess l t'along the bisector' plane of the angle between the insorts I5; I 5 and to'enter alternativelyinto one or other of a plurality (here four) of slots l8 formed longitudinally in the surfaceof the body I6 to hold the body against rotation with respect-to the table;

To releasably lock the body in the position shown, there isprovided the device embodying the invention proper; comprises a normally horizontal clamp member 20, whose" left end is proportioned to overhang the recess l4 and is provided with a pressure member I9 of more or less resilient material, e. g. leather, sponge rubber, or the like, arranged to lie tangentially against a body It in the recess I4. A bolt 2| having an elongated cylindrical head 22 provided with a transverse bore 23 is threadedly engaged in the table I l beside the recess M to stand axially perpendicular to the normal length of the clamp 20, which is formed with a cylindrical bore 24, and with slots 25, 25 corresponding in size and location with the ends of the bore 23 in the bolt head 22, so that a pin 26 may be passed therethrough to lock theclamp 20 slidably on the bolt head 22. The right hand end of the clamp 20 is transversely bored and counterbored as shown to house two plungers 2'! and springs 28 therefor held in place by threaded abutments 29, 29.-

The outer ends of the plungers abut against the table H and tend to urge the righthand end of the clamp away from the table,and-there by tend to move the clamp 20 away from the "table as far as the pin 26 in the slots will'allow the clamp to slide on the bolt head 22. v

A cam lever 30 is formed as a yoke whose ends bestride the middle and left hand portions of the .clamp 20, and arepivoted on the pin 26. The two pivot ends of the lever 30 are formed as cams 3|, 3 I, as best shown in Fig l, so that, when the lever is in the position show in full lines in Fig. 1, the cams 3| acting against abutments 32, 32 formed on the clamp 20 will drive the clamp 29 along the bolt head 22 toward the table I l against the urge of the springs 2-8, whereas when the lever 30 is swung into the position shown inbroken lines in Fig.1, the clamp 20 sfree to move away from the table along the bolt head 22 under the urge of the springs 28. The outerend of the lever '30 is preferably provided with a large transversely flat handle portion 33 having a finger hole 34. Between the table II and the clamp 20 there is a resilient washer 35 on the bolt 2|, preferably of soft rubber or the like, to keep the clamp 20 from beingcramped in its sliding on the bolt head 22 by the offset force of the springs 28.

In operation, assuming the various parts in the positions shown in solid lines in- Fig. 1 and as shown in Figs. 2 and 3, and assuming that itis desired to rotate the crystal holder body IE or to replace it by another, the lever 30 is swung forwardto the position indicated inFig. 1 in broken lines and is then turned on its axis clockwise. The finger hole is to facilitate the first of these motions; and the broadfiat blade-like handle 33 is provided to facilitate the second. Swinging the lever 30 forward as described releases the clamp 20 from the inward pressure of'thecam 3| and the clamp 20 moves out on the bolt head 22 under the combined urges of the compressed rubber washer 35 and of the springs 28 until the washer is wholly uncompressed and the plunger 21 stops against the bottom of the counterbore 36 housing it in the clamp. The bolt head 22, the bore 24, the plunger 21', the counterbore36, and the cams 3|, 3| are all so proportioned and arranged that when the cams are withdrawn by turning the lever 30 forward to the broken line position, the pad |9 no longer presses against the crystal holder body It, the washer 35 is no longer under pressure between the-clamp 20 and thetable ll,

and the plunger 21 no longer presses against the table although there may still be bare contact turn the bolt 2| together with the entire assembly thereon and especially the clamp 20, thus swinging the left end of the clamp 2|] up and to the right and clear of the opening of the recess M. In the particular case illustrated, the bolt 2| and the bore 3'1, in which the bolt is held in the table I, are formed with complementary left hand screw threads, so that, as the bolt is turned it also backs out of the table by a quarter of the pitch length of its thread, further ensuring the disengagement of the plungers 21 from the face of the table II and the release of pressure from the washer 35. The way is thus cleared to remove the crystal holder body Hi from the recess M, to be turned as required and replaced with the pin engaged in another of the slots l8, or to be replaced by another crystal holder.

' The particular arrangement shown is designed to be revolved counterclockwise about the axis or theshaft I2 to lap the crystals 38. Were this rotation in the other direction the necessary arrangementwould be the mirror image of that shown and the bolt 2| would have a right hand instead of a left hand thread. The essential of this detail is that the bolt 2| must be so threaded that when the outswung lever 30 is turned to swing the padded end of the clamp 20 clear of the opening of the recess I 4, the rotation of the bolt 2| thus efiected will back the bolt a fractional turn out of its threaded housing and the plungers 21 will be drawn back positively out of contact with the table ,|,l. Then, when the operation is reversed byturning the lever 30 counterclockwise, the plungers cannot overhang and snub on the edge of the table.

What is claimed is:; 1

1. In an apparatus having a supporting member provided with rigid positioning means against at one or more of the three points.- Now rotating the lever 3 ll clockwise as one looks along its axis causes the lever, acting throughthe' pin: 26, to

which an article is to be pressed and clamped, the combination therewith of clamping means comprising a screw threaded bolt having a transverse bore in the head thereof, and engaged in a correspondinglythreaded hole in the supporting member adjacent to the positioning means thereon, a clamping bar mounted on the head of the bolt to be slidable thereon axially ofthe bolt and to have one end overhang the positioning means, and formed with slots registering with the transverse bore in the head of the bolt and elongated axially of the bolt, 'a' cam lever: having one end thereof bifurcated and receiving the clamping bar therebetween'and formed with bores registering with the bore in the head of the bolt, a pivot pin rigidly mounted in the bore in the head of the bolt and passing through the slots in the clamping bar to guide the same in axially sliding freedom of motion only on the-bolt and engaged in the bores of the cam lever to provide a fulcrumtherefor, cam surfaces formed on the cam lever to engage abutments formed on the clamping bar to move the "same along the bolt head toward the positioning means in one position of the lever and release the same to be moved away from the positioning means in another position of the lever, a resilient contact pad mounted on the face of the clamping bar overhanging the positioning means, and a spring pressed plunger mounted in the opposite end of the clamping bar from the contactpad to engage and resiliently press against thesupporting member.

2. In an apparatus having-a supporting member provided with rigid positioning means against which an article is'to be pressed and clamped, the combination therewith of clamping means comprising a screw threaded bolt having a transverse bore in the head thereof, and engaged in a correspondingly threaded hole in the supporting member adjacent to the positioning means thereon, a clamping bar mounted on the head of the bolt to be slidable thereon axially of the bolt and to have one end overhang the positioning means, and formed with slots registering with the transverse bore in the head of the bolt and elongated axially of the bolt, a cam lever having one end thereof bifurcated and receiving the clamping bar therebetween and formed with bores registering with the bore in the head of the bolt, a pivot pin rigidly mounted in the bore in the head of the bolt and passing through the axially sliding freedom of motion only on the bolt and engaged in the bores of the cam lever to provide a fulcrum therefor, cam" surfaces formed on the cam lever to engage abutments formed on the clamping bar to move the same along the bolt head toward the positioning means in one position of the lever and release the same to be moved away from the positioning means in another position of the lever, a resilient contact pad mounted on the faceof the clamping bar overhanging the positioning means, a spring pressed plunger mounted in the opposite end of the clamping bar from the contact pad to engage and resiliently press against the supporting memher, and a resiliently compressible collar about the shank of the bolt and interposed between the supporting member and the clamping bar.

WALTER R. SCHERB. 

